Hi Culisa,
Sorry, my family background is Croatian, but I was born in Australia, so my reading/writing in Croatian is not all that good.
For discrimination, the few people that use DD coils here in Australia on a GPX tend to use smaller coils, as they are using them in very trashy areas, so separation between targets is more important than depth. In areas that are less trashy, we just dig all targets, so this is where the bigger coils come in.
I have personally never used a large DD for discrimination, so never thought to try the Iron Reject on the 15" Detech DD. I have used the 15x12" SEF DD on the beaches, and the iron reject works very well.
Between the 15" DD Detech and 15x12" Commander, the Detech is deeper and more sensitive, but is slightly heavier.
The Commander being a semi-elliptical would get between trash a little better, but there won't be much in it. If you are looking for maximum depth on small-medium size targets, as well as very good depth on big objects, go the Detech 15". It is great in Sens Extra and DD position.
If you have very trashy sites, like 4 or more targets on each swing, and still want to go deep, have a look at the Nokta Fors CoRe with the big coil, or CTX3030 with the 17" coil.
Nenad
